Heater



FIG. 1 is a front perspective view of a heater showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is a rear perspective view thereof.

The broken lines showing features of the design are for the purpose of illustration only and form no part of the claimed design. 

CLAIM The ornamental design for a heater, as shown and described. 